Merge branch 'andrasmaroy-master'

Author: djmaze

README.md

@@ -35,6 +35,8 @@ You can prevent services from being updated by appending them to the `IGNORELIST
 
 Alternatively you can specify a filter for the services you want updated using the `FILTER_SERVICES` variable. This can be anything accepted by the filtering flag in `docker service ls`.
 
+You can set Shepherd to roll back a service to the previous version if the update fails by setting the `ROLLBACK_ON_FAILURE` variable.
+
 You can enable private registry authentication by setting the `WITH_REGISTRY_AUTH` variable.
 
 If you need to authenticate to a registry (for example in order to get around the [Docker Hub rate limits](https://www.docker.com/increase-rate-limit)), you can set the variables `REGISTRY_USER` and `REGISTRY_PASSWORD`. If you are not using Docker Hub but a private registry, set `REGISTRY_HOST` to the hostname of your registry.
@@ -62,6 +64,7 @@ Example:
                         --env APPRISE_SIDECAR_URL="apprise-microservice:5000" \
                         --env IMAGE_AUTOCLEAN_LIMIT="5" \
                         --env RUN_ONCE_AND_EXIT="true" \
+                        --env ROLLBACK_ON_FAILURE="true" \
                         --mount type=bind,source=/var/run/docker.sock,target=/var/run/docker.sock,ro \
                         --mount type=bind,source=/root/.docker/config.json,target=/root/.docker/config.json,ro \
                         mazzolino/shepherd

shepherd

@@ -52,7 +52,19 @@ update_services() {
       else
         logger "Trying to update service $name with image $image" "true"
 
-        docker service update "$name" $detach_option $registry_auth $no_resolve_image_flag --image="$image" > /dev/null
+        if ! docker service update "$name" $detach_option $registry_auth $no_resolve_image_flag --image="$image" > /dev/null; then
+          logger "Service $name update failed!"
+          if [[ "${ROLLBACK_ON_FAILURE+x}" ]]; then
+            logger "Rolling $name back"
+            docker service update "$name" $detach_option $registry_auth $no_resolve_image_flag --rollback > /dev/null
+          fi
+          if [[ "$apprise_sidecar_url" != "" ]]; then
+            title="[Shepherd] Service $name update failed"
+            body="$(date) Service $name failed to update to $(docker service inspect "$name" -f '{{.Spec.TaskTemplate.ContainerSpec.Image}}')"
+            curl -X POST -H "Content-Type: application/json" --data "{\"title\": \"$title\", \"body\": \"$body\"}" "$apprise_sidecar_url"
+          fi
+          continue    # continue with next service
+        fi
 
         previousImage=$(docker service inspect "$name" -f '{{.PreviousSpec.TaskTemplate.ContainerSpec.Image}}')
         currentImage=$(docker service inspect "$name" -f '{{.Spec.TaskTemplate.ContainerSpec.Image}}')